All zones are weak.

[jcom]

Homeowner called with "pressure" problem. Just bought the house and thought there may have been a pump that was removed. Home has 53 psi. All zones are weak. Using 5-6 Maxi-Paws with 15-17 gpm nozzles per zone.

I want to renozzle down to 13-14 and see if I can get them to work enough so that at least they will rotate.
Some zones also have spray heads on them as well. What a piece of work! If needed I will renozzle those with MP Rotators to gain some gpm.

Any ideas on my "solution" to the problem.

Thanks folks,

John

[PurpHaze]

Wow... here we go again guessing what was originally put in that worked. :)

Start with the main line and POC. What size is it and what size are the valves?

Are you saying each Maxi-Paw is putting out 15-17 GPM and the whole zone is putting out 75+ GPM?

[jcom]

1" PVC to a manifold on the side of the house. 1" DV 100 valves.

I checked the nozzles on each head and total gpm is 15-17on the Maxis.

Homeowner is not sure a pump was in place. Her theory.
I don't know if the system ever worked. System is perhaps
5-6 yrs. old.

Thanks

John

[jcom]

1" supply. 1" meter also.

My apologies for the omissions. Early morning is my excuse this time.

John

[PurpHaze]

1" PVC to a manifold on the side of the house. 1" DV 100 valves.

I checked the nozzles on each head and total gpm is 15-17on the Maxis.

1" supply. 1" meter also.

After checking the Rainbird site on the Maxi Paw specs, by all indications they should work fine. Both types I looked at will work as low as 25 PSI depending on nozzles.

Lower the nozzles and see if the new nozzles make them work better. (Indicate exactly which nozzle is being used and the exact Maxi Paw model.)

[jcom]

After looking at the POC that is in place, I think a pump may have been in place before the house was sold. Using the pipe configuration as a clue.

The pressure is adequate, but the design and nozzles are to blame. As it is, the maxis will not rotate as they should.

I am going to change those nozzles that are overwatering and see what happens.


Thanks Purp for all the help.


John

[PurpHaze]

After looking at the POC that is in place, I think a pump may have been in place before the house was sold. Using the pipe configuration as a clue.

You're prolly on the right track. If the lower nozzles don't help you may have to totally change the sprinkler head types or reinstall a booster pump.

[Wet_Boots]

Maxipaws have better low-pressure capabilities than just about any rotor. Nozzles can be swapped, to reduce consumption (and raise supply pressure) ~ also, and this is important, there is an adjustment for the impact arm spring, that you need to make for low pressures and small nozzles. That alone can restore operation.

[Remote Pigtails]

there is an adjustment for the impact arm spring, that you need to make for low pressures and small nozzles. That alone can restore operation.

I did not know that boots and I thought I was a maxi-paw expert. One of my favorite heads.

[Wet_Boots]

For the black and red nozzles, the adjustment should be made as standard practice.

[jcom]

Thanks WB. I knew about the spring position. When visiting with the homeowner about my plan to change the nozzles, she told me she thought it took an awful long time to draw her bathwater.

What perplexes me is that even with the nozzles in place, they "should" still operate. At least some of the zones.
I have seen many other systems with more flow through a 1" system and they work fine. The only things inline are the meter and the backflow. But if in fact the flow to the house is poor as well, the meter would be the target if the supply to the house was providing what it should. I have no experience as to if a meter can be restrictive in some way.

But I will bet that someone here has! How about recommendations for finding actual flow through the meter? Without making a big mess downstairs?

Thanks again,

John

[Wet_Boots]

We assume you have checked for partially closed shut-off valves.

[jcom]

Yep, there is a shutoff on the meter on the supply pipe where it comes into the downstairs utility room.

I seem to remember some type of flow/psi gauge available referenced on this site a while back.

Thanks for help, Boots.

John

[Wet_Boots]

What's the backflow? Has it been checked?

[jcom]

The system has a Wilkins or Watts 1" PVB. I have not checked anything in that regard as I have not experienced any restriction in the past from the PVB.

I searched and found WB's info on the Toro flow gauge. I don't understand how it can give accurate flow to be expected through a 1" system by hooking up to a 1/2" fed faucet connection.

Thanks,

John

[Wet_Boots]

A 'stuck' DCVA had come to mind. That Toro device was conceived when one inch water meters were a rarity. It more conforms to flows you get from a hose bib on a house with 3/4" service. As an alternative, you can take a flow/pressure measurement, and the static pressure, and mathematically produce a performance curve. I have an old HP calculator with the formula programmed into it.

[jcom]

Thanks for info, Boots.

Time to hit the streets. Will do some more sleuthing and see what I can find.

John

[bicmudpuppy]

Is timing the meter w/ a stop watch while a zone is running not an option? If you want to tax it beyond that, turn on the garden hose with a zone running or manually open more than one valve. A combination of these flow rates should give you an idea.

[Wet_Boots]

Maybe someone can find a page with the mathematical formula I put in the calculator. I've seen the info in print before. What it does, is allow an accurate prediction of flow rates for pressures you haven't measured. Say you run 8.5 gpm, as measured by a flow gauge or (even better) a water meter, with a 75 psi pressure at the meter. Those two numbers, along with the static pressure, can predict flows for lower meter pressures. Or predict meter pressures for different flows.

There was a cruder variation of the formula, provided in an old Safe-T-Lawn cataog. Instead of the exponential formula, a table of 'ratios and multipliers' was given, since no one had scientific calculators back then. It was by plotting the numbers in their table onto logarithmic graph paper, that the exponential formula became evident.

[jcom]

I will try the meter and stopwatch, Bic. Thanks. I can also cut into the PVC supply, install a T, fittings, and do a bucket test and I'll know for sure what I have available. If needed, I could do this before the PVB and also after. I don't know how to see if the PVB is restricting or not by another way.

Thanks for all the input.

John

[Mike Leary]

I will try the meter and stopwatch, Bic. Thanks. I can also cut into the PVC supply, install a T, fittings, and do a bucket test and I'll know for sure what I have available. If needed, I could do this before the PVB and also after. I don't know how to see if the PVB is restricting or not by another way.

Thanks for all the input.

John

I'm trying to find the cut sheet for a gpm/psi tester that we've used for years
to replace the Toro "lite". Made in Michigan, gpm to 40, psi to 110, will do
more research, mucho better than the bucket IF you have a q.c.!